Emily is 44 years old and Nadia is 12 years old. How many years will it take until Emily is only 3 times as old as Nadia?
Solution: We can use the given information to write down an equation about how many years it will take. Let $y$ be the number of years that it will take. In $y$ years, Emily will be $44 + y$ years old and Nadia will be $12 + y$ years old. At that time, Emily will be 3 times as old as Nadia. Writing this information as an equation, we get: $44 + y = 3 (12 + y)$ Simplifying the right side of this equation, we get: $44 + y = 36 + 3 y$ Solving for $y$ , we get: $2 y = 8$ $y = 4$.